Validity of Resistive Index in Intracranial Pressure Monitoring among Questionable Hydrocephalic Infants

Abstract
Background: Resistive Index (RI) measurement by Tran-scranial Doppler sonography was used as a bedside safe, noninvasive technique that helpful for the assessment of vascular hemodynamics in various conditions; such as defect in brain perfusion associated with hydrocephalus.
Objective: To evaluate validity of resistive index as reflecting Intracranial Pressure (ICP).
Patients and Methods: This is a cross-sectional study which included thirty infants with query hydrocephalus, and they underwent RI measurement of middle cerebral artery at Radiology Department of Benha University Hospital then ICP monitoring at the Neurosurgery Department of Benha University and Benha Children Hospitals through the period from April 2015 to January 2017.
Results: This study includes thirty infants with query hydrocephalus, twenty four boys and six girls, with mean age 5.83±3.43 (ranged from 1 to 12 months). There is direct correlation between RI and ICP as RI increase with increasing ICP, which is statistically significant (p<0.05). As regard RI, there is significant difference between infants with high ICP and others with normal ICP (p=0.001). The best detected RI cut off point among infants is 0.7 as it has high sensitivity, specificity and accuracy.
Conclusion: RI is valid as a predictor of increased ICP so it can be used as a successful non invasive method instead of invasive technique for evaluating intracranial pressure in diagnosis of hydrocephalus among infants.